Pontiac FIREBIRD 1972 Service Manual page 753

6D-10 1972 PONTIAC SERVICE MANUAL
IDLE SPEED CHART
I
CURB IDLE IRPM)
1
Manual Automatic FAST SOLENOID
I
I
ENGINE
1
~ransmissionl
.
/
~ransmisionl
I
IDLE
(
ACTIVE
~ s o l e n o ~ d Inactive
Manual Transmiss#on Only
3 ~ . ~ . ~ .
V A L V E E N G I N E SPEED ( P L U N G E R E X T E N D E D ) 8 5 0 M A N .
6 5 0 A U T O .
REMARKS: Make adjurtmentrw~th engine at normal operating temperature, choke open,
AIC off, auto. trans. in drwe, park brake on, disconnected vacuum hoses
plugged.
Fig. 6D-16 Idle Speed Chart
CURB IDLE SETTING PROCEDURE (Fig. 6D-16)
IMPORTANT: All carburetors are fitted with
locked mixture screws. DO NOT TAMPER
WITH SCREWS, or exhaust emission levels
may be adversely affected.
When service of the throttle body is necessary, follow the
instructions presented below for optimum emissions con-
trol.
NOTE: Make adjustments with engine at nor-
mal operating temperature, choke open, and
A/C OR Plug disconnected vacuum fittings.
CAUTION: Set parking brake and block dn've
wheels.
V-8 PROCEDURE
1. Disconnect carburetor "evap" hose from vapor canis-
ter.
2. Disconnect carburetor to vacuum solenoid hose at
vacuum solenoid and plug hose. Disconnect throttle
solenoid wire (4 Bbl.).
3. Set dwell and initial ignition timing (in that order) at
specified Idle RPM (Fig. 6D-15, 6D-16).
4. a. Adjust carburetor speed screw to specified RPM
(Fig. 6D-16) with automatic transmission in Drive.*
b. On 4 Bbl. models, reconnect throttle solenoid
wire. Manually extend solenoid screw and adjust
to specified RPM (Fig. 6D-16).
With auto. trans. in Park (man. trans. in Neutral),
check fast idle speed with fast idle speed screw (4
Bbl.) on top step of fast idle cam. Adjust to specified
RPM (Fig. 6D-16) by turning fast idle speed screw (4
Bbl.). Refer to Section 6B for WGD fast idle adjust-
ment.
NOTE:
ZGV
fist idle speed is non-adjustable.
Reconnect distributor advance and vapor canister
hoses.
6 CYL. PROCEDURE
Disconnect fuel tank "evap" hose from vapor canis-
ter.
Disconnect distributor vacuum hose at distributor
and plug hose.
Set Dwell and Timing (in that order) at specified Idle
RPM.
Adjust carburetor speed screw to specified RPM*.
DO NOT ADJUST SOLENOID SCREW
**.
With auto. trans. in Park (man. trans. in Neutral),
check fast idle speed with fast idle tang on top step
of fast idle cam. Adjust to specified RPM as shown
in Fig. 6D-16.
IDLE MIXTURE ADJUSTMENT
NOTE: The idle mixture should be reset only if
the carburetor throttle body has been over-
hauled or replaced. The following procedure
must be used to adjust idle speed and mixture:
1. With mixture screws backed out approximately 3 1/2
turns from lightly seated position, adjust carb. speed
screw to specified idle speed on all models.
2. Turn mixture screws I N an even amount until the
idle speed shown in Fig. 6D- 16 is attained.
IDLE MIXTURE ADJUSTMENT
I
ENGINE
'
Solenoid Active
1 MV Carburetor
350 V-8
'
400 V-8
455 V-8
455 H.O.
MANUAL
2 Bbl. 14 Bbl.'
AUTOMATIC
2 Bbl.
1
4 Bbl.'
875
--
--
--
/OO
700
700
---
--
1075
--
1075
--
775
725
.
775